Our EBSD analysis delved into the history of these fault rocks, revealing several stages of fault movement and mineral crystallisation. The images below are orientation maps of calcite and celestine respectively. In this figures, the colour reflects the orientation of the crystal and a gradient shows how the structure has been deformed within the crystal.
The calcite shows areas of small crystals that are the result of recrystallisation during faulting, as well as a large amount of twinning. In geology, crystal twinning is caused by adjacent crystals of the same mineral that share points of their crystal lattice in a symmetrical orientation. Celestine grows as fine fibrous crystals, and this is made very obvious in EBSD. The celestine here infills the newly opened fault.